This invention relates to ground clamps suitable for making electrical connections between a grounding conductor and an earth ground, such as a metal pipe.
A variety of devices have been utilized for making electrical ground connections between a ground wire and a ground pipe. One such device includes a perforated copper strap with a screw and first nut for clamping the strap onto a pipe, and with a second nut for clamping a wire to the strap. The perforated strap provides for attaching the unit to various diameters of pipe. The strap is limited in the size of pipe to which it can be attached, and several lengths of strap are sometimes provided.
Another prior art ground clamp consists of two cast iron saddles fastened about a pipe with screws. A ground wire terminated in a lug is attached under one of the screws. A third screw is threaded in one of the saddles and has a pointed end for making electrical contact with the pipe. This type of clamp requires many sizes of saddles to accommodate a range of pipe sizes. Also when used on copper water pipe, the third screw can and often does dent and collapse the pipe.
These prior art devices have been satisfactory in some applications. However at the present time there is need for making ground connections with larger conductors, such as a solid number 6 wire which is in the order of 1/8 inch diameter. It is very difficult to make wrap around type connections with wire of this size and one solution has been to attach a lug or similar component to the ground wire and then bolt the lug to a ground strap or ground band. This type of connection requires additional parts and additional time in making the connection.
Ground wires may be of any size and either solid or stranded. At the present time, wires of size numbers 6 and 14 are widely used and typically two different sizes of ground clamps are required to accommodate them, a number 6 wire having a cross-section area more than six times that of a number 14 wire.
It is an object of the present invention to provide a new and improved ground clamp which can be used for making electrical ground connections between various sizes of ground wire and various sizes of pipe, and in particular a ground clamp which can be utilized with wire in the size range of number 6 to number 14, either solid or stranded.
It is another object of the invention to provide such a ground clamp which can utilize conventional pipe bands or hose clamps and requires only one additional component.
Other objects, advantages, features and results will more fully appear in the course of the following description.